|  | 2.2 |
Full-Duplex Transmitting, Fast Ethernet Standard and LAN Segmentation
| 2.2.1 | Full-duplex Ethernet

Full-duplex Ethernet allows the transmission of a packet and the reception of a different packet at the same time. This simultaneous transmission and reception requires the use of two pairs of wires in the cable and a switched connection between each node. This connection is considered point-to-point and is collision free. Because both nodes can transmit and receive at the same time, there are no negotiations for bandwidth. Full-duplex Ethernet can use an existing shared medium as long as the medium meets minimum Ethernet standards. To transmit and receive simultaneously, a dedicated port is required for each node. Full-duplex connections can use 10BASE-T, 100BASE-TX, or 100BASE-FX media to create point-to-point connections. The network interface cards (NICs) on both ends need to have full-duplex capabilities. The full-duplex Ethernet switch takes advantage of the two pairs of wires in the cable. This is done by creating a direct connection between the transmit (TX) at one end of the circuit and the receive (RX) at the other end. With these two stations connected this way, a collision-free domain is created because the transmission and receipt of data occurs on separate non-competitive circuits. Ethernet usually can only use 50%-60% of the 10-Mbps available bandwidth because of collisions and latency. Full-duplex Ethernet offers 100% of the bandwidth in both directions. This produces a potential 20-Mbps throughput- 10-Mbps TX and 10-Mbps RX.
| Web Links
| MSE
| Spurgeon's Ethernet Site
| Ethernet Tutorials